Illusion setting vs prong setting in diamond ring, wedding ring or engagement ring.Illusion setting was invented by Oscar Massin, from France back in the late 1860s. This is a jewelry design or technique of a prong setting with a shiny metal plate around the girdle of a faceted gemstone namely popular one are diamond ring, wedding ring or engagement ring, maximizing the size of the diamond. It diffuses the outline of the diamond causing the enhancing effect.